/******************************************************************************

    Copyright (C) 2006 Alessio Stalla (alessiostalla@gmail.com)

    This file is part of PrettyProlog.

    PrettyProlog is free software; you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
    the Free Software Foundation; either version 2 of the License, or
    (at your option) any later version.

    PrettyProlog is distributed in the hope that it will be useful,
    but WITHOUT ANY WARRANTY; without even the implied warranty of
    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
    GNU General Public License for more details.

    You should have received a copy of the GNU General Public License
    along with PrettyProlog; if not, write to the Free Software
    Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA

    See the file COPYING for further details.

 *****************************************************************************/

package prettyprolog.engine.listeners;

import prettyprolog.engine.Frame;

/**
 * This class represents an event occurred in a Stack, such as the push or pop of a Frame.
 * Since most Stack events are about Frames, this class holds a reference to a Frame for
 * convenience, altough such a reference is not always meaningful for all kinds of stack
 * events.
 */
public class StackEvent {

    private Frame frame;

    /** Constructs a new StackEvent */
    public StackEvent(Frame fr) {
	frame = fr;
    }

    /** @return the Frame associated to this event (if any). */
    public Frame getFrame() {
	return frame;
    }

}
